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- Beal, Jacob, et al.
(author)
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Robust estimation of bacterial cell count from optical density
- 2020
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In: Communications Biology. - : Springer Science and Business Media LLC. - 2399-3642. ; 3:1
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Journal article (peer-reviewed)abstract
- Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data.
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| 2. |
- Zeng, Jinshu, et al.
(author)
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Acute physiological, perceived exertion andenjoyment responses during a 4-weekbasketball training: a small-sided game vs.high-intensity interval training.
- 2023
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In: Frontiers in Psychology. - : Frontiers Media S.A.. - 1664-1078. ; 14
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Journal article (peer-reviewed)abstract
- Introduction: Although previous research found that small-sided game (SSG) trainingwas more enjoyable than high-intensity interval training (HIT) in various sports, no datawere provided during longer training period in basketball. Furthermore, the comparisonof internal loads between the two training approaches needs to be further examined.Thus, this study aimed to examine the acute physiological, perceived exertion andenjoyment responses during 4-week progressive basketball SSG or HIT programs.Methods: Nineteen female collegiate basketball players were randomly assigned totwo groups that performed either HIT (n = 10) or SSG (n = 9) 3 times per week for4 continuous weeks. Average and percentage of maximal heart rate (HRmean and%HRmax), rating of perceived exertion (RPE), and physical activity enjoyment (PACES)were determined during each training session.Results: There was a main group effect in PACES (p < 0.001; η p2 = 0.44, moderate),and SSG had higher PACES than HIT in each week (p < 0.05). There were no significantinteractions or main group effects in HRmean, %HRmax or RPE, but a main time effectwas found in HRmean (p = 0.004; η p2 = 0.16, minimum), %HRmax (p < 0.001; η p2 = 0.25,minimum), and RPE (p < 0.001; η p2 = 0.31, moderate), respectively. In the SSG group,although no significant differences were found in HR responses, %HRmax was below90% in week 1 and week 2. Accompanied with changes in %HRmax, RPE in week 1 andweek 2 was lower than that in week 3 and week 4 (p < 0.05).Conclusion: Our findings suggest that SSG and HIT elicit similar acute HR responseand RPE level, but SSG is perceived as more enjoyable and therefore it is more likely toincrease exercise motivation and adherence comparing to HIT. Moreover, it seems thathalf-court, 2 vs. 2 SS Gtraining format with modified rules and lasting ≥ 7.5min shouldbe prescribed as an enjoyable training alternative to provide optimal cardiovascularstimuli (> 90% of HRmax) for female basketball players.
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